(88 days)
The R3 Constrained Liner Acetabular System is a cemented or uncemented prosthesis intended to replace a hip joint. The Constrained Liner is intended for primary or revision patients at high risk for hip dislocation due to a history of prior dislocation, bone loss, soft tissue laxity, neuromuscular disease, or intra-operative instability and for whom all other options to constrained acetabular components have been considered. The R3 Constrained Liner is intended for single use only.
The R3 Constrained Liners were previously cleared for market notification K083566. In August of 2010, Smith & Nephew launched a voluntary recall of the devices due to reports of intraoperative distocations .- The subject devices have been modified to address the intraoperative failure mode. Design features have been incorporated into the inner locking and support ring components of the R3 Constrained Liner construct which increase the device's resistance to dislocation under dynamic loading. The R3 Constrained Liners are available with inner diameters of 22 and 28mm and outer diameters from 52mm through 66/70mm. The devices are assembled from components that are made of ASTM F75 CoCr, ASTM F90 CoCr, ASTM F1472 Ti-6Al-4V, and ASTM F648 UHMWPE.
The provided text describes a medical device submission (K111635) for a modified R3 Constrained Liner to the FDA. The submission focuses on demonstrating substantial equivalence to previously cleared devices through mechanical testing, not through a clinical study involving human readers or AI. Therefore, most of the requested information regarding acceptance criteria for AI performance, sample sizes for test sets, expert involvement, and ground truth establishment, is not applicable to this document.
However, I can extract the relevant information regarding the device itself and the type of evaluation performed.
Here's a breakdown of the information based on your request and what's available in the document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state acceptance criteria in a quantitative, measurable format like a table for specific performance metrics (e.g., accuracy, sensitivity, specificity) as one would expect for an AI/CADe device. Instead, the "acceptance criteria" for this device, which is a physical implant, are implicitly met by demonstrating substantial equivalence to predicate devices through mechanical testing.
The "reported device performance" is a qualitative statement of equivalence.
| Performance Aspect | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Mechanical | The modified R3 Constrained Liner components must demonstrate sufficient attachment loads (push-in, push-out, shuck-out) and increased resistance to dislocation under dynamic loading, equivalent to existing, legally marketed predicate devices, and demonstrate no new issues related to safety and effectiveness. This is in response to a previous recall due to intraoperative dislocations. | "Mechanical testing has been conducted to address the attachment loads (push-in, push-out, shuck-out) of the R3 Constrained Liner components as well as to address the new failure mode (dislocation). A review of the results indicates that the R3 Constrained Liners are equivalent to existing, legally marketed predicate devices with regards to mechanical performance and that there are no new issues related to the safety and effectiveness of the subject devices." |
| Overall | The modified R3 Constrained Liner must be substantially equivalent to the predicate devices (K083566, K021803, K033442) in terms of function, intended use, indications for use, material composition, and overall design. | "The subject devices are identical in function, intended use, indications for use, and material composition, and very similar in overall design to the R3 Constrained Liners cleared via premarket notification K083566." |
| "Based on the similarities to the predicate components and a review of the mechanical testing performed, the devices are substantially equivalent to above predicate constrained hip systems." |
The following points are not applicable to this submission because it is for a physical medical device (hip implant), not an AI/CADe device that performs analysis or diagnosis. The evaluation was based on mechanical testing and comparison to predicates, not a clinical study involving experts or human-in-the-loop performance.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Not Applicable. This document describes mechanical testing of a physical device, not a test set for an AI algorithm.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- Not Applicable. Ground truth for an AI algorithm is not relevant here. The "ground truth" for this device would be its mechanical integrity, which is assessed through engineering tests.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not Applicable. There was no test set in the context of AI evaluation.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- Not Applicable. No MRMC study was conducted, as this is not an AI-assisted diagnostic device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not Applicable. This is a physical implant, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Not Applicable. The "ground truth" for the device's performance would be the results of the mechanical tests proving its structural integrity and resistance to dislocation.
8. The sample size for the training set
- Not Applicable. There is no AI training set for this physical device.
9. How the ground truth for the training set was established
- Not Applicable. There is no AI training set.
§ 888.3310 Hip joint metal/polymer constrained cemented or uncemented prosthesis.
(a)
Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted to replace a hip joint. The device prevents dislocation in more than one anatomic plane and has components that are linked together. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular component made of ultra-high-molecular-weight polyethylene with or without a metal shell, made of alloys, such as cobalt-chromium-molybdenum and titanium alloys. This generic type of device is intended for use with or without bone cement (§ 888.3027).(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Class II Special Controls Guidance: Hip Joint Metal/Polymer Constrained Cemented or Uncemented Prosthesis.”